When connectors having a number of terminals are mated, the mating resistance generated between mating contacts in both of the connectors becomes greater. Hence, it is generally difficult to mate the connectors by pushing the connectors by hand. For this reason, several kinds of what are called lever-type connectors with sliding cams, which utilize a toggle for reducing the operational force for mating, have been proposed.
As connectors of such a type, for example, the connectors shown in FIG. 13 to FIG. 15 are known (see JP 2003-132996 A).
The known connector 101 shown in FIG. 13 is configured to mate with a known mating connector 150, and includes a pair of sliders 102, a lever 130, and a wire cover 140.
As shown in FIG. 14, a contact receiving portion 112 having multiple contact receiving passageways 111 that extend in the front-rear direction (in FIG. 13, the lower side denotes front side and the upper side denotes rear side) is positioned in the housing 110. Each of the contact receiving passageways 111 receives a metal contact (not shown) connected to an electrical wire (not shown). In addition, a pair of upper and lower slider receiving slots 113 (in FIG. 13, the front side in the drawing denotes upper side and the rear side in the drawing denotes lower side) that open at both of left and right end surfaces (in FIG. 13, the left side denotes left side and the right side denotes right side) are defined in the housing 110.
Furthermore, lever receiving grooves 114 that open along the rear surface of the housing 110 are provided in the housing 110 and along the outside of each of the slider receiving slots 113.
In addition, a sealing member 115 is positioned along the outer circumference of the contact receiving portion 112. The sealing member 115 seals the known mating connector 150 that mates with and the contact receiving portions 112. Additionally, the sealing member 115 prevents water from entering from the mating portion side into the contact receiving passageways 111.
Furthermore, each of the sliders 120 is formed to have a plate shape, and is movably received in the slider receiving slot 113. The inner surface of each slider 120 includes a cam groove 121 into which a cam pin 152 positioned along a mating portion 151 of the known mating connector 150 is inserted, as shown in FIG. 13. Also, the outer surface of each slider 120 includes a pin portion 122 that is inserted into an interlocking groove 133, to be described later, positioned on the lever 130.
Moreover, the lever 130 extends in such a manner that a pair of arms 132 each having a plate shape extend from both ends of an operational portion 131. Each of the arms 132 includes a pin opening 134, as shown in FIG. 13. The lever 130 is supported for rotation with respect to the wire cover 140 by making the pin opening 134 fit with a supporting shaft 141 positioned substantially in the middle of the left-right direction of the wire cover 140. Additionally, each of the arms 132 includes the interlocking groove 133 from an outer peripheral edge toward the pin opening 134. Hereinafter, in each of the arms 132, the side on which the operational portion 131 is positioned will be referred to as front side, whereas the side on which the pin opening 134 is positioned will be referred to as rear side.
Furthermore, the wire cover 140 is attached along the rear side of the housing 110 to extend position a bundle of electrical wires extended from the housing 110 to one side in the left-right direction of the housing 110 (to the right side in FIG. 13, to the front side in the drawing in FIG. 14).
In order to assemble the known connector 101 and the known mating connector 150, firstly, the lever 130 and the sliders 120 are arranged at unmated positions, so that the mating portion 151 of the known mating connector 150 mates the front side of the known connector 101. Then, the cam pins 152 of the known mating connector 150 enter the inlets of the cam grooves 121 positioned at the slider 120, so both connectors 110 and 150 are brought into a temporary mating state. Subsequently, when the lever 130 in the unmated position is rotated toward the mated position in an arrow X direction, the interlocking groove 133 positioned at the lever 130 pushes the pin portions 122 of the sliders 120. Thus, the sliders 120 interlock with the lever 130 to move from the unmated position to the mated position. The action of the cam groove 121 and the cam pin 152 causes both of the connectors 101 and 150 to be pulled closer to each other and brought into the mating state. Conversely, when the lever 130 at the mated position is rotated toward the unmated position in the opposite direction to the arrow X direction, the sliders 120 interlock with the lever 130 to move from the mated position to the unmated position. The action of the cam groove 121 and the cam pin 152 separate both of the connectors 101 and 150 from each other.
In this manner, as to the known connector 101, the toggle structure where the lever 130 that rotates and the sliders 120 that interlock with the lever 130 and that has the cam groove 121 is employed. Thus, the mating and unmating operational forces can be reduced considerably.
Moreover, as connectors of such a type, there are disclosed the connector having a projection for temporarily mating the cam pin at each of the inlets of multiple cam grooves, into which the corresponding multiple cam pins are inserted, respectively (see JP H10-255902 A).
In the conventional connector, however, an operator conducts the mating operation between the connector and the mating connector in a situation where the operator is not able to confirm the mating portion visually, in some cases. When the operator conducts the mating operation in such a manner, the lever is rotated with the connector that is obliquely located with respect to the mating portion of the mating connector. This results in twisting during mating, and thus damage may occur to the connector.
Its concrete example will be described below.
In FIG. 16 and FIG. 17, a mating portion 151 of the known mating connector 150 includes three pairs of cam pins 152a to 152c. The mating portion 151 has a rectangular frame shape, and is composed of: a pair of installed surfaces (side surfaces) 151a, opposing each other, provided with the cam pins 152a to 152c; and a pair of end surfaces 151b for coupling the pair of installed surfaces 151a. The cam pins 152a (hereinafter, referred to as first cam pin) located at the front side of the arm portion 132 of the known connector 101 are spaced away from one of the end surfaces 151b by a distance d1. Additionally, the cam pins 152c (hereinafter, referred to as third cam pin) located at the rear side of the arm portion 132 of the known connector 101 are spaced away from the other of the end surfaces 151b by a distance d2 (where d1>d2).
As shown in FIG. 16A, when the housing 110 and the mating portion 151 are mated with each other in a state where the known connector 101 is mated with the known mating connector 150 with such a configuration while the known connector 101 is tilting to the rear side of the arm portion 132, there is a possibility that the first cam pins 152a are not properly mated with can grooves (hereinafter, referred to as first cam groove) corresponding to the first cam pins 152a, as shown in FIG. 16B and FIG. 16C.
On the other hand, as shown in FIG. 17A, when the housing 110 and the mating portion 151 are mated with each other in a state where the known connector 101 is mated with the known mating connector 150 with such a configuration while the known connector 101 is tilting to the front side of the arm portion 132, there is a possibility that the third cam pins 152c are not properly mated with cam grooves (hereinafter, referred to as third cam groove) corresponding to the third cam pins 152c, as shown in FIG. 17B and FIG. 17C.
When the lever is rotated in the state shown in FIG. 16, so-called twisting during mating occurs. Since the distances from the end surface 151b of the mating portion 151 to the first cam pins 152a are longer than those to the third cam pins 152c, a large amount of stress is applied to the first cam pins 152a in which the mating is not certain. There is a possibility of damaging the first cam pins 152a. 
Meanwhile, when the lever 130 is rotated in a state shown in FIG. 17, further stress is applied to the third cam pins 152c in which the mating is not certain. However, since the distances from the end surface 151b of the mating portion 151 to the first cam pins 152a are shorter than those to the third cam pins 152c, the resistance to the rotation of the lever 130 is made larger. For this reason, the operator often notices an abnormality before damaging the third cam pins 152c. 
In this manner, when the known connector 101 is mated with the known mating connector 150 having plural cam pins, positioned on both ends, with different distances from the end surface 151b, there is a possibility of damaging the cam pins with longer distances from the end surface 151b. An improvement is needed.